This invention relates generally to a material blend to make non-stick cookware, although this invention is also applicable to make a variety of other food processing, domestic and industrial apparatus, tools or molds used to form end products that take the shape of the tool or mold after the subjection to a predetermined temperature for a predetermined time.
Conventional cookware used in, for example, baking, is made from wood, steel, or aluminum, although other materials such as copper, glass or ceramics are used. However, these materials have many shortcomings. For example, wood harbors bacteria and black algae and cannot be properly sanitized. Wood and plastics cannot be used in the cooking or baking process because of the excessive heat required. Also, the downtime associated with cleaning these materials after use is a further disadvantage based on the amount of time and labor spent scrubbing the cookware. Further, a number of these pieces of cookware are needed for the different stages of baking, cooking and freezing.
Conventional cookware made from these materials also requires excessive flour, cornmeal, butter or oil be added prior to baking to avoid the food products from sticking after baking. These additives increase the fat content and reduce the health benefit of the foods. Parchment paper has also been used to avoid sticking, but is typically used once and thrown away causing environmental concerns.
Further, the removing and releasing of the food product from conventional cookware after baking occasionally results in substantial damage to the food products, especially when dealing with fragile bakery items such as muffins and certain breads. While removing these fragile bakery items from conventional cookware, utensils and other kitchen tools, such as a spatula, are sometimes required in addition to the butter or oil to remove them from the cookware. The use of these additional tools is cumbersome and may also damage the cookware.
As an alternative, an enamel or glazing composition has been applied to the surface of cookware for providing a non-stick coating. Conventional, non-stick coatings consist of a fluorocarbon layer such as polytetrafluoroethylene (PTFE) or silicone elastomer applied directly to a metal substrate. Such coatings, however, tend to degrade with use and, in some instances, the coating material flakes away from the substrate and into the food product. These coatings also require re-application periodically, e.g. every six months, to maintain their non-stick properties.
Another alternative to conventional cookware uses a composition of fabric materials consisting of woven, knitted or non-woven fibers of glass fibers, carbon fibers, or ceramic fibers impregnated and coated with food grade silicones as disclosed in U.S. Pat. No. 5,232,609 assigned to ETS Guy DeMarle of Pont-Remy, France. Such material, however, could potentially flake off into the food product and cause a serious health hazard.
The shortcomings of the prior art may be alleviated by using the apparatus made from the material blend of a fluoropolymer component and a silicone rubber component in accordance with one or more principles of the present invention. The apparatus of the present invention may be used in the baking industry, confectionary industry, delicatessen trade or other food processing trade or industry. The apparatus formed by this blend may also be used in other domestic and industrial applications to form products that take the shape of the mold, such as, for example, ice cubes, candles, soap, pet biscuits, certain types of castings, or the like. Additionally, other uses may be made of the invention which fall within the scope of the claimed invention but which are not specifically described herein.
In one aspect of the invention, there is provided a non-stick apparatus for forming a viscous material into an end product after subjection to a predetermined temperature for a predetermined time. The apparatus comprises a planar portion having at least one cavity. The at least one cavity is defined by a side wall extending downwardly from the planar portion towards a closed end. The side wall and the closed end receives the viscous material and defines the end product of the viscous material after the subjection to the predetermined temperature for the predetermined time. The planar portion, the side wall and the closed end are integrally formed from a blend consisting essentially of a fluoropolymer component and a silicone rubber component.
In one embodiment, the blend comprises less than 70% by weight of the silicone rubber component. In an alternate embodiment, the blend comprises less than 65% by weight of the silicone rubber component. In yet another embodiment, the blend comprises 0% by weight of the silicone rubber component.
In another aspect of the invention, there is provided a process for converting a liquid or semi-solid material to an end product. The process comprises at least partially filling a cavity of an apparatus with said liquid or semi-solid material. The apparatus comprises a planar portion which defines the cavity. The cavity is further defined by a side wall extending downwardly from the planar portion towards a closed end. The planar portion, the side wall and the closed end are integrally formed from a blend consisting essentially of a fluoropolymer component and a silicone rubber component. The process further comprises subjecting the at least partially filled apparatus to a predetermined temperature for a predetermined time, whereby said liquid or semi-solid is converted to the end product.
Additional advantages are provided using the blend of fluoropolymer and silicone rubber. Tools, molds, trays, cookware or the like formed from this material blend are reusable and provide non-stick properties eliminating the need for oil, butter or other non-stick additives. The use of this material blend also eliminates the transfer of odors or taste, or other contaminates, to the ultimate product being formed by the apparatus formed by the blend.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments, applications and aspects of the invention are described in detail herein and are considered a part of the claimed invention.